Interconnect structure with cavity having one or several contact rises on the wall of the cavity and method for producing same

ABSTRACT

The invention concerns an interconnect device comprising a support ( 200 ) in which at least one hole is formed, the hole having walls forming a closed contour and being formed by a cavity ( 203 ) and one or several slots ( 205   a - 205   b   , 215   a - 215   b ) communicating with the cavity, the slots extending in a direction making a non-zero angle with the main plane of the support, several conducting elements ( 214 ) being positioned on at least one wall of the hole and passing through the latter part, the conducting elements each being intended to connect conducting areas to each other that are situated on either side of the support, at least one of said slots separating two of said conducting elements from each other.

TECHNICAL FIELD

The present invention concerns the field of microelectronics andmicrosystems, and more particularly that of interconnect structures inparticular made during steps commonly called “waferlevel packaging”(WLP) steps, i.e. steps for making integrated circuit packages made on awafer before cutting into elementary circuits.

It provides an improved interconnect structure with one or severalcontact rises in a cavity formed in a support in order to connectelements to each other that are situated on either side of the support,as well as a method for producing such a structure.

BACKGROUND OF THE INVENTION

The document “Spin, Spray coating and Electrodeposition of photoresistfor MEMS structures—A comparison”, Pham et al., Delft University ofTechnology, DIMES, presents interconnect structures including a contactrise made on the inclined walls of a cavity, with a conductive elementmaking it possible to establish a contact between a conductive areasituated in the cavity and another element situated above the cavity.

The production of contact rises poses a problem when the walls of thecavity are vertical.

Document WO 01/45172 presents a method for making a three-dimensionalinterconnect structure that is formed by producing slots by sawing theedge of a support, then depositing a metal material in said slots.

The interconnect structures thus formed must be situated near the edgesof the support.

The problem arises of finding a new interconnect structure, that doesnot have the aforementioned drawbacks, and that is easier to implement,and a method for producing such a structure.

BRIEF DESCRIPTION OF THE INVENTION

The invention first concerns an interconnect device comprising a supportin which at least one hole is formed, the hole having walls forming aclosed contour and being formed by a cavity and one or several slotscommunicating with the cavity, at least part of the slots extendingalong the hole, the device also comprising one or several conductiveelements positioned on at least one wall of the hole and passing throughthe latter part, the conductive elements each being intended to connectconductive areas to each other that are situated on either side of thesupport.

According to one possible embodiment, at least one of said slotsseparates two of said conductive elements from each other.

According to one possible embodiment, the device can include at leastone conductive element housed in one of said grooves and extending alongsaid slot.

The cavity can pass through the thickness of the support.

According to one alternative, the cavity can be formed by a blindorifice formed in the support.

The support can be formed by several substrates and/or superimposedlayers.

The cavity can be formed by a first opening made in a first substrateand a second opening with a section different from the first opening andmade in a second substrate.

The slots can communicate with said first opening, one or several otherslots formed in the second substrate along the cavity formed in saidsubstrate communicating with the second opening.

The walls of the cavity can be covered with a conductive material. It isthus possible to form a protection against electromagnetic disruptionson the perimeter of the cavity.

The invention also concerns a method for producing an interconnectdevice as defined above, and comprising the steps consisting of:

-   -   forming conducting pads passing through a support,    -   forming a cavity in the thickness of the support so as to open        and remove part of the conducting pads, the other part of the        pads being kept and forming conducting elements housed in        grooves.

The invention also concerns a method for producing an interconnectdevice as defined above, the method comprising the steps consisting of:

-   -   forming a cavity in the thickness of a support,    -   forming an area with a conducting base covering the walls of the        cavity,    -   forming at least one slot so as to open the conducting material,        the slot communicating with the cavity.

The invention also concerns a method for producing an interconnectdevice as defined above, the method comprising the steps consisting of:

-   -   forming a cavity in the thickness of a support and slots        communicating with said cavity and extending over all or part        thereof,    -   forming a layer of sacrificial material in the slots, so as to        separate the slots from the cavity,    -   forming a conducting layer on the walls of the cavity,    -   removing the layer of sacrificial material so as to remove        portions of the conducting layer between the slots and the        cavity.

The invention also concerns a method for producing an interconnectdevice as defined above, comprising the steps consisting of:

-   -   forming a cavity in the thickness of the support,    -   forming at least one slot communicating with said cavity and        extending over all or part thereof, said slot being made such        that it has, in a plane parallel to the support, a variable        section with a narrowing at the connection between the slot and        the cavity,    -   performing a directional deposition of conducting material on        said wall and on part of the slot.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood upon reading thedescription of embodiments provided purely for information andnon-limitingly in reference to the appended drawings, in which:

FIGS. 1A-1B illustrate a first example of an interconnect structureaccording to the invention, provided with a contact rise made in acavity,

FIG. 2 illustrates a second example of an interconnect structureaccording to the invention, including conducting elements passingthrough a cavity and that are electrically insulated from each other viatrenches communicating in the cavity,

FIGS. 3A-3B illustrate a third example of an interconnect structureaccording to the invention, provided with a cavity and slots in whichconnecting elements pass,

FIGS. 4A-4B illustrate a fourth example of an interconnect structureaccording to the invention, provided with contact rises passing througha cavity and insulated from each other by slots formed along the cavityin which connecting elements are provided,

FIG. 5 illustrates a fifth example of an interconnect structureaccording to the invention,

FIG. 6 illustrates a sixth example of an interconnect structureaccording to the invention, in which contact rises are formed all aroundthe cavity,

FIG. 7 illustrates a seventh example of an interconnect structureaccording to the invention provided with a cavity covered withconducting material insulated from a conducting element passing throughthe cavity via slots formed against the walls of the cavity,

FIGS. 8A-8C illustrate an example of a support made up of twosuperimposed substrates in which cavities are formed,

FIGS. 9A-9B illustrate another example of an interconnect structureaccording to the invention, formed in a cavity with several parts ofdifferent sections, each part including conducting areas insulated fromeach other by slots formed along the walls of the cavity, slots formedin one part of the cavity communicating via trenches with other slotsformed in another part,

FIGS. 10A-10B illustrate another example of an interconnect structureaccording to the invention, formed in a cavity with several parts ofdifferent sections, each part including conducting areas insulated fromeach other by slots formed along the walls of the cavity,

FIGS. 11A-11B illustrate another example of an interconnect structureaccording to the invention, formed in a blind cavity,

FIGS. 12A-12B illustrate another example of an interconnect structureaccording to the invention, made in a blind cavity, contact rises beingprovided on the entire perimeter of the cavity,

FIG. 13 illustrates an example of an interconnect structure according tothe invention, formed in a blind cavity and connected to interconnectvias emerging at the bottom of the blind cavity,

FIG. 14 illustrates an alternative of the example of an interconnectstructure provided in FIG. 13,

FIGS. 15 to 17 illustrate another example of an interconnect structureaccording to the invention with a blind cavity formed in a support inthe form of two superimposed substrates between which an anisotropicconducting film is provided,

FIGS. 18A-18B illustrate an embodiment of a cavity in a support in thecontext of the implementation of an interconnect structure according tothe invention,

FIGS. 19A-19B illustrate an embodiment of an interconnect structureaccording to the invention,

FIGS. 20 and 21 illustrate a support formed by two substrates assembledby gluing in which a cavity is made,

FIGS. 22A-22C illustrate an example of a method for making aninterconnect structure according to the invention,

FIGS. 23A-23B illustrate another example of a method for making aninterconnect structure according to the invention,

FIGS. 24A-24B illustrate another example of a method for making aninterconnect structure according to the invention,

FIGS. 25A-25D illustrate another example of a method for making aninterconnect structure according to the invention,

FIGS. 26 and 27 illustrate another example of a method for making aninterconnect structure according to the invention,

FIGS. 28A-28B, 29A-29B, 30A-30E illustrate an example of a method formaking an interconnect structure with contact rise in a cavity andintegrating such a structure into an imager device,

FIG. 31 illustrates an example of an optical device provided with acavity in which an interconnect structure according to the invention canbe formed,

FIG. 32 illustrates an example of a MEMS device provided with a cavityin which an interconnect structure according to the invention can beformed,

FIGS. 33A-33B illustrate an example of an embodiment of horizontaltrenches.

Identical, similar, or equivalent parts of the different figures bearthe same numerical references so as to facilitate the transition fromone figure to the next.

The different parts shown in the figures are not necessarily shown usinga uniform scale, to make the figures more legible.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

A first example of an interconnect structure implemented according tothe invention is provided in FIGS. 1A-1B (FIG. 1A showing the structurein a top view while FIG. 1B illustrates the structure in a transversecross-sectional view, the cutting plane being indicated in FIG. 1A).

The structure is made in a support 100 that can for example assume theform of a layer, or of a stack of several layers, or of a substrate, orof a stack of several substrates, or of an interposer, and includes acavity 103 passing through the thickness of the support between itsupper face (shown in FIG. 1A) and its lower face.

The support 100 can for example be made of a semiconductor material, oran insulating material, for example glass.

The interconnect structure makes it possible to connect elements ordevices situated on either side of the lower face and the upper face ofthe support. The interconnect structure may be made in a central area ofthe support.

A vertical wall of the cavity 103 is covered with elements 104 a, 104 b,104 c, with a base of a conducting material 106 such as copper,aluminum, or tungsten, or polysilicon, for example.

The conducting elements 104 a and 104 b can assume the form of platescovering a vertical wall of the cavity 103 (the vertical direction beingdefined as a direction parallel to the vector {right arrow over (k)} ofthe orthogonal reference [O; {right arrow over (i)}; {right arrow over(j)}; {right arrow over (k)}] provided in the figures).

The conducting elements 104 a, 104 b are separated from each other via aslot 105 a communicating with the cavity 103 and formed at said verticalwall, while another slot 105 b separates the conducting elements 104 band 104 c. These slots 105 a, 105 b extend in the vertical direction andpass through the thickness e of the support 100 which, in this example,corresponds to the height h of the cavity 103.

The slots 105 a, 105 b and the cavity 103 communicating with the latterparts form a hole whereof the vertical walls form a closed contour.

The slots 105 a, 105 b and the cavity 103 can have been madesimultaneously or successively, for example by etching such as DRIE(Deep reactive ion etching) or laser etching.

The slots 105 a, 105 b make it possible to ensure an electricaldiscontinuity between the conducting elements 104 a, 104 b, 104 c.

Thus, the conducting elements 104 a, 104 b, 104 c are not connected toeach other or electrically connected to each other.

In this example, one of the conducting elements 104 b is extended by aconducting track 107 b that extends over the upper face of the support100 parallel to the main plane thereof (the main plane of the supportbeing defined as a plane passing through the latter part and parallel tothe plane [O; {right arrow over (i)}; {right arrow over (j)}] given inthe figures).

The through conducting elements 104 a, 104 b, 104 c each make itpossible to connect a device situated on or above the upper face of thesupport 100 and another device situated under or below the lower face ofthe support 100.

According to one alternative (FIG. 2), the conducting elements 104 a,104 b, 104 c can be extended by conducting tracks 107 a, 107 b, 107 c,respectively, that extend on the upper face of the support 100.

Another example of an interconnect structure is provided in FIGS. 3A-3B.

In this other example, vertical connecting elements 114 a, 114 b with abase of a conducting material in the form of conducting lines are alsopositioned in the slots 105 a, 105 b, and pass through the thickness ofthe support 100. The elements 114 a, 114 b, like the slots 105 a, 105 b,form a non-zero angle in relation to the main plane of the support andare, in this example, perpendicular to the main plane of the support.

The connecting elements 114 a, 114 b only cover a portion of the wallsof the slots 105 a, 105 b.

The connecting elements 114 a, 114 b are extended by conducting tracks117 a, 117 b, respectively, that extend on the upper face of the support100.

In the example provided in FIGS. 4A-4B, the structure includesconducting elements 104 a, 104 b, 104 c on a wall of the cavity 103 andconnecting elements 114 a, 114 b in the slots, the connecting elements114 a, 114 b in the slots are connected to conducting tracks 117 a, 117b, which extend on the upper face of the support, while the conductingelement 104 b is also connected to a track 107 b resting on the support.

The connecting elements 114 a, 114 b only cover a portion of the slots105 a, 105 b, the latter parts making it possible to ensure anelectrical discontinuity between the connecting elements 114 a, 114 band the conducting elements 104 a, 104 b, 104 c. The slots 105 a, 105 bmake it possible to separate and electrically insulate the connectingelements 104 a, 104 b, 104 c, of the conducting elements 114 a, 114 b.

In the example of FIG. 5, relative to the example previously described,the conducting elements 104 a, 104 c are also electrically connected tothe conducting tracks 107 a, 107 c, positioned on the upper face of thesupport 100.

One example of a structure with a cavity 103 whereof the vertical wallsare each covered with conducting elements, the conducting elements 104a, 104 b, 104 c, 104 d, 104 e, 104 f, 104 g, 104 h being separated by asuccession of slots 105 a, 105 b, 105 c, 105 d, 105 e, 105 f, 105 g, 105h, formed all around the cavity 103 is provided in FIG. 6.

Another example of an interconnect structure formed in the cavity 103 isillustrated in FIG. 7. In this example, the vertical walls of the cavity103 are completely covered by a conducting area 114, which also coverspart of the upper face of the support 100.

A connecting element 104 b formed on a vertical wall of the cavity 103is separated and disconnected from the conducting area 114 by verticalslots 105 a, 105 b communicating with the cavity 103.

The connecting element 104 b is extended by a conducting track 107 bthat extends on the upper face of the support 100.

A support area that is not covered with conducting material separatesthe conducting track 107 b from the conducting area 114, such that theconducting area 114 and the conducting track 107 b are not electricallyconnected.

As illustrated in FIGS. 8A-8C (FIG. 8B illustrating the device accordingto a top view while FIGS. 8A and 8C show transverse cross-sectionalviews), an interconnect structure according to the invention can be madein a cavity 203 formed by several parts 203 a, 203 b with differentdimensions in the thickness of a support 200.

The cavity or cavities 203 can be formed by a first part 203 a, havinggiven dimensions, and a second part 203 b situated in the extension ofthe first part, the second part 203 b having, in a plane parallel to thesupport, smaller dimensions than the first part 203 a, the first part203 a and the second part 203 b being defined by walls forming a stairprofile. The stair configuration can make it possible for example tohouse a lens in the first part 203 a and position it in relation to animager using the second part 203 b while also allowing an electricalcontact rise along the stair-shaped cavity.

According to one possible embodiment, a stair profile including morethan 2 stairs can be implemented.

The support 200 can possibly be made up of several layers or severalstacked substrates, for example two layers 200 a, 200 b or twosubstrates 200 a, 200 b, which can be assembled by gluing, for example.

To that end, a glue seam 211 can for example be provided between the twosubstrates 200 a, 200 b.

This glue seam 211 can be, according to a first case, formed so as toarrive in the cavity 203 (FIG. 20) or so as to be arranged withdrawn inrelation to the walls of the cavity 203 (FIG. 21).

The first substrate 200 a can include vertical slots 205 a, 205 bcommunicating with the first part 203 a of the cavity 203 and formed ina wall of said first part 200 a, while the second substrate 200 bincludes vertical slots 215 a, 215 b communicating with the second part203 b of the cavity 203 and formed in a wall of said second part 203 b.

In FIGS. 9A-9B, an example of an interconnect structure provided with asupport in which such a cavity 203 is formed, is provided.

In this structure, a first conducting area 214 covers a portion of theupper face of the first substrate 200 a, part of the vertical walls ofthe first part 203 a of the cavity 203, a portion of the upper face ofthe second substrate 200 b situated at the bottom of said first part 203a, as well as a portion of the vertical walls of the second portion 203b of the cavity 203.

A second conducting area 216, separate from the first conducting area214, is formed by a conducting strip 107 b extending on the upper faceof the first substrate 100 a, extended in a portion covering a verticalwall of the first part 103 a of the cavity, a portion of the upper faceof the second substrate 100 b situated at the bottom of said first part103 a, as well as a portion of the vertical walls of the second portion103 b of the cavity 103.

The first conducting area 214 and the second conducting area 216 areseparated and electrically insulated from each other via vertical slots205 a, 205 b formed in the first substrate 200 a, 200 b, horizontaltrenches 208 a, 208 b (the horizontal direction being defined as adirection parallel to the plane [O; {right arrow over (i)}; {right arrowover (j)}] of the orthogonal reference [O; {right arrow over (i)};{right arrow over (j)}; {right arrow over (k)}] given in the figures)formed on the second substrate 200 b and communicating with the slots205 a, 205 b, and vertical slots 215 a, 215 b formed in the secondsubstrate 200 b. The slots 205 a, 205 b, 215 a, 215 b communicate withthe cavity.

Another example of an embodiment of horizontal trenches 208 a, 208 b isgiven in FIGS. 33A-33B (the support being shown without conducting areain FIG. 33A).

In this other example, conducting areas 218 a extend along trenches andinclude conducting areas that extend along the latter parts.

The trenches 208 a, 208 b can be formed such that their mouth is smallerthan their bottom.

This can make it possible to form conducting areas 218 a, 218 b thatonly cover a portion of the bottom of the trenches.

These areas 218 a, 218 b can in fact be made by metal deposition, themetal only being deposited, by shadow effect due to the shape of thetrenches 208 a, 208 b, on a portion of the bottom of the trenches.

According to one alternative of the previously described example (FIGS.10A-10B), the horizontal trenches 205 a, 205 b, formed in the secondsubstrate 200 b, are replaced by areas 206 a, 206 b of the secondsubstrate 200 b that are exposed and not covered with conductingmaterial.

An interconnect structure with a “blind” cavity 303 can also be provided(FIGS. 11A and 11B).

In this case, the cavity 303 can be formed in the thickness of a firstsubstrate 200 a, resting on a second substrate 200 b, the cavity 303passing through the thickness of the first substrate 200 a, and having abottom at the second substrate 200 b and that can be formed by the upperface thereof.

A portion of the upper face of the first substrate 200 a, part of thewalls of the cavity, as well as the upper face of the second substrate200 b are covered with a conducting area 314.

A metal track 207 b extends on the upper face of the first substrate 200a, on a wall of the cavity 303, and on the upper face of the secondsubstrate 200 b.

This metal track 207 b is separated and electrically insulated from theconducting area 314 via slots 105 a, 105 b formed in the walls of thecavity, as well as areas of the substrates 100 a, 100 b that are notcovered with metal material.

Another example of an interconnect structure with a blind cavity isprovided in FIGS. 12A-12B. Slots 205 a, 205 b, 205 c, 205 d, 205 e, 205f, 205 g, 205 h, are formed all around the cavity and electricallyinsulating conducting elements 307 a, 307 b, 307 c, 307 d, 307 e, 307 f,307 g, 307 h from each other, each formed by a conducting trackextending over the first substrate 200 a, a conducting area covering onewall of the cavity, and another conducting track extending to the bottomof the cavity 303 on the second substrate 200 b.

According to one possible embodiment, the conducting elements 307 a, 307b, 307 c, 307 d, 307 e, 307 f, 307 g, 307 h, can be connected to vias317 passing through the second substrate 100 b (FIG. 13).

An alternative of this structure is provided in FIG. 14 and providesconducting elements 407 h, 407 d each formed by a conducting stripextending on the first substrate 100 a, a conducting area covering awall of the cavity, and another conducting strip situated between thefirst on the second substrate 100 b, said other conducting strip beingconnected to a via 317.

In the examples of structures of FIGS. 15, 16, 17, interconnect areas350 formed by metal tracks 351 in a layer of dielectric material 352 areprovided between the first substrate 100 a and the second substrate 100b, and make it possible to establish a connection between the conductingelements 307 h, 307 d of the first substrate 100 a and other conductingelements of the second substrate 100 b, for example vias 317 passingthrough the second substrate 100 b (FIG. 15) or metal areas 318 restingon the second substrate 100 b (FIG. 16) or metal areas 319 coveringportions of two faces of the second substrate 100 b, as well as walls ofan opening going through the second substrate 100 b(FIG. 17).

As illustrated in FIGS. 18A and 18B, the cavity of the interconnectstructure previously described can be formed once the substrates 100 aand 100 b have been assembled and connected.

FIGS. 19A-19B illustrate an example of an embodiment of an interconnectstructure in which the bottom and the walls of a blind cavity 303 arecovered with a metal layer 416 at which metal strips 407 a, 407 b, 407c, 407 d, 407 e, 407 f, 407 g, 407 h resting on the first substrate 100a are formed.

Vertical slots 205 a, 205 b, 205 c, 205 d, 205 e, 205 f, 205 g, 205 hformed all around the cavity 303 and communicating therewith insulateareas of the metal layer from each other in a direction orthogonal tothe substrate (FIG. 19A).

Then, portions of the metal area 416 are removed from the bottom of thecavity 303.

The removal can be done such that the metal layer 416 is removed betweengrooves situated opposite each other on opposite walls of the cavity303.

One example of a method for making a cavity provided with insulatingslots as provided in an interconnect structure according to theinvention is illustrated in FIGS. 22A-22C.

Pads 101 a, 101 b are first formed in the thickness of a support 100,which can be in the form of a layer or a stack of layers or a substrate(FIG. 22A).

The pads 101 a, 101 b can be conducting pads for example with a base ofa metal material such as copper, aluminum, or tungsten, or polysilicon.These pads can be vias insulated through a thickness of dielectricmaterial surrounding them.

A cavity 103 is then formed going through the support 100.

The cavity 103 is made so as to go through a portion of the supportwhere part of the conducting pads 101 a, 101 b is situated, and then toopen and remove a portion of the conducting pads 101 a, 101 b (FIG.22B).

In the example of a production method of FIGS. 23A-23B, conducting pads201 a, 201 b are first formed with a significant size in the support(FIG. 23A).

A cavity 103 is then formed going through the support 100 and an areawhere the conducting pads 201 a, 201 b are situated, and so as to openand remove a significant portion of the latter parts and keep anotherportion against a flank of the cavity 103 (FIG. 23B).

According to another example method, it is possible first to form acavity 103 going through a support 100, then to cover the walls of thecavity using an area 108 of conducting material (FIG. 24A).

In the case where the support 100 has a base of semiconductor material,an insulating layer (not shown) can be deposited beforehand on thevertical walls of the cavity.

Slots 105 a, 105 b are then formed at the level of at least one verticalwall of the cavity, the slots 105 a, 105 b communicating with the cavity103.

The slots 105 a, 105 b are made so as to remove portions of the area 108of conducting material.

At the end of this removal, a first conducting area 108 a covering partof the walls of the cavity 103 is separated from a conducting area 108 bcovering a part of a wall of the cavity 103, via slots 105 a, 105 b(FIG. 24B).

According to another example method, the cavity 103 and the slots 105 a,105 b are formed in a support 100, at the same time or one after theother (FIG. 25A).

A layer of sacrificial material 109 is then deposited in the slots 105a, 105 b or on the walls of the slots 105 a, 105 b, the sacrificialmaterial 109 being distributed so as to form a separation between thecavity 103 and the slots 105 a, 105 b (FIG. 25B).

The layer of sacrificial material 109 can be provided so as to protrudein the cavity 103.

The sacrificial material 109 can for example be SiO₂ or Si₃N₄.

A layer of conducting material 108 is then deposited so as to cover thewalls of the cavity 103 and cover the sacrificial material 109.

The material can for example be deposited by PVD (physical vapordeposition).

The thickness of the conducting material 108 can be provided to besmaller than the thickness of the layer of sacrificial material 109protruding in the cavity 103 (FIG. 25C). The layer of sacrificialmaterial 109 is then removed, which causes a removal of the conductingmaterial 108 opposite the slots 105 a, 105 b for example by wet chemicaletching.

At the end of this removal, the conducting area 108 is in the form oftwo separate conducting parts 108 a and 108 b that are not connected toeach other and are separated using slots 105 a, 105 b (FIG. 25D).

One example of a method for producing an interconnect structure isprovided in FIGS. 26 and 27.

In this example, in the support 100, a cavity 103 is made going throughthe support 100, as well as at least one vertical slot 105 extending inthe thickness of the support 100, and communicating with the cavity 103.

The slot can for example have a rectangular (FIG. 26) or oval (FIG. 27)section.

Parts 106 a, 106 b of a wall 104 of the cavity 103 form a separationbetween the latter part and the slot 105.

A metal deposition 108 is then done so as to cover a wall of the cavityand part of the slot 105. The parts 106 a, 106 b prevent a deposition ofmetal all around the slot such that the metal deposition on the wall 104of the cavity and on the slot 105 forms a discontinuous area.

The metal deposition may be a so-called “directional” deposition inwhich the material is dispensed along a predetermined angle in relationto the main plane of the support (the main plane of the support being aplane passing through the latter and parallel to the plane [O; {rightarrow over (i)}; {right arrow over (j)}] of the orthogonal reference [O;{right arrow over (i)}; {right arrow over (j)}; {right arrow over (k)}]given in the figures).

By shadow effect, the parts 106 a, 106 b prevent a metal deposition onthe perimeter of the slot.

It is thus possible to make a connecting element 104 b along the slot,which is disconnected from the conducting elements 104 a and 104 cformed on said wall during the metal deposition.

Another example of a method for making an interconnect structure isprovided in FIGS. 28A-28B, and 29A-29B (FIGS. 28A-28B providing a topview, while FIGS. 29A-29B provide a transverse cross-sectional viewwhereof the cutting plane is indicated in FIGS. 28A-28B).

The interconnect structure can be made from a support 200 can possiblybe made up of several layers or several stacked substrates, for exampletwo layers 200 a, 200 b or two substrates 200 a, 200 b, which can beassembled by gluing, for example, using a glue seam 211.

A cavity 303 in the form of a blind orifice is provided in the firstsubstrate 200 a. Vertical slots 105 a, 105 b, i.e. orthogonal to themain plane of the support 200, were formed at a wall of the cavity andcommunicate therewith. Portions of the glue seam 211 are exposed by thecavity 303.

In this embodiment, the first substrate 200 a includes at least onemetal track 404 on its rear face, i.e. the face situated opposite thesecond substrate 200 b (FIGS. 28A and 29A).

Sacrificial material is then deposited in the slots 105 a, 105 b, thenmetal material 414 is deposited in the cavity 303 and on the support300.

The sacrificial material is then removed, then patterns are formed inthe metal material, for example in a metal area 415 covering walls ofthe cavity 303, connected to a metal track 417 a on the upper face ofthe support.

This step also leads to the formation of another metal area 416separated from the metal area 415 by slots, covers a wall portion of thecavity situated between the slots 105 a, 105 b, and is extended byanother metal track 417 b formed on the upper face of the support (FIGS.28B and 29B).

The interconnect structure with a cavity that has just been formed canbe integrated or assembled with another device.

FIGS. 30A-30E show a method for making an imager device including suchan interconnect structure.

This method can be done from the structure previously formed (anddescribed in connection with FIG. 30A showing the device of FIG. 28B ina cross-sectional view C′C).

One or several vias 430 are then formed passing through the secondsupport 200 b as well as one or several connecting pads 432 on saidsupport 200 b, the pads being connected 432 to the vias (FIG. 30B).

An optical component C, for example a fixed focal lens, a parallelplate, or a variable focal device is then placed in the cavity 303 andconnected to the conducting area 415 formed in said cavity (FIG. 30C).

An imager substrate is then attached on the upper face of the firstsubstrate 200 a, the imager substrate being assembled and connected tothe metal tracks 417 a, 417 b formed on the upper face of the firstsubstrate 200 a (FIG. 30D).

An opening is then made in the second substrate 200 b, opposite theoptical component C (FIG. 30E).

An interconnect structure with a cavity as implemented according to theinvention can be applied in the field of MEMS components, for examplesuch as inertial sensors, accelerometers or gyrometers (FIG. 31).

FIG. 32 shows an example of a unitary camera made up an active opticalelement 500 set on the top of cavity 303, focused on the imagersubstrate.

Contact rises are implemented in the cavity 303 to power said activeoptical element.

1. An interconnect device comprising a support formed by severalsuperimposed substrates and/or layers in which at least one hole isformed, the hole having walls forming a closed contour and being formedby a cavity and one or several slots communicating with the cavity, thecavity is formed by a first opening made in a first substrate and asecond opening, with a different section from the first opening and madein a second substrate, the slots extending over all or part of thelength of the hole, one or several conducting elements being positionedon at least one wall of the hole and passing through the latter part,the conducting elements each being intended to connect conducting areasto each other situated on either side of the support.
 2. Theinterconnect device according to the preceding claim, at least one ofsaid slots separating two of said conducting elements from each other.3. The interconnect device according to claim 1, including at least oneconducting element housed in one of said slots and extending along saidslot.
 4. The interconnect device according to claim 1, the cavitypassing through the thickness of the support.
 5. The interconnect deviceaccording to claim 1, the bottom of the cavity is blind.
 6. Theinterconnect device according to claim 1, said slots communicating withsaid first opening, one or several other slots formed in the secondsubstrate along the cavity formed in said substrate communicating withthe second opening.
 7. The interconnect device according to claim 1, thewalls of the cavity being covered with conducting material.
 8. A methodfor making an interconnect device according to claim 1, comprising thesteps consisting of: forming conducting pads passing through a support,forming a cavity in the thickness of the support so as to open andremove part of the conducting pads, the other part of the pads beingkept and forming conducting elements housed in grooves.
 9. A method formaking an interconnect device according to claim 1, comprising the stepsconsisting of: forming a cavity in the thickness of a support, formingan area with a conducting base covering the walls of the cavity, formingat least one slot so as to open the conducting material, the slotcommunicating with the cavity.
 10. A method for making an interconnectdevice according to claim 1, comprising the steps consisting of: forminga cavity in the thickness of a support and slots communicating with saidcavity and extending over all or part thereof, forming a layer ofsacrificial material in the slots, so as to separate the slots from thecavity, forming a conducting layer on the walls of the cavity, removingthe layer of sacrificial material so as to remove portions of theconducting layer between the slots and the cavity.
 11. A method formaking an interconnect device according to claim 1, comprising the stepsconsisting of: forming a cavity in the thickness of the support, formingat least one slot communicating with said cavity and extending over allor part thereof, said slot being made such that it has, in a planeparallel to the support, a variable section with a narrowing at theconnection between the slot and the cavity, performing a directionaldeposition of conducting material on said wall and on part of the slot.12. An interconnect device comprising a support in which at least onehole is formed, the hole having walls forming a closed contour and beingformed by a cavity and one or several slots communicating with thecavity, the slots extending over all or part of the length of the hole,one or several conducting elements, intended to connect conducting areasto each other situated on either side of the support, covering at leastpart of the walls of the cavities and only a portion of the slots, theslots ensuring an electrical discontinuity between the connectingelements in the slots and the conducting elements of the cavity.
 13. Theinterconnect device according to the preceding claim 12, the cavitypassing through the thickness of the support.
 14. The interconnectdevice according to claim 12, the cavity being formed by a blind orificeformed in the support.
 15. The interconnect device according to claim12, the support being formed by several superimposed substrates and/orlayers.
 16. The interconnect device according to claim 12, the supportbeing formed by several superimposed substrates and/or layers, thecavity being formed by a first opening made in a first substrate and asecond opening with a section different from the first opening and madein a second substrate.
 17. The interconnect device according to claim 1,the bottom of the cavity is blind, said slots (205 a, 205 b)communicating with said first opening (205 a), one or several otherslots (215 a, 215 b) formed in the second substrate (200 b) along thecavity formed in said substrate communicating with the second opening(203 b).
 18. A method for making an interconnect device according toclaim 12, comprising the steps consisting of: a. forming a cavity in thethickness of the support, b. forming at least one slot communicatingwith said cavity and extending over all or part thereof, said slot beingmade such that it has, in a plane parallel to the support, a variablesection with a narrowing at the connection between the slot and thecavity, c. performing a directional deposition of conducting material onsaid wall and on part of the slot.